CA2094497C - Polyolefin pressure-sensitive adhesive compositions containing macromonomers - Google Patents

Abstract

The invention provides pressure-sensitive adhesive (PSA) compositions comprising a graft copolymer of one or more of ethylene and C3-C18 .alpha.-olefins and one or more of a new class of macromonomers. The adhesive composition comprises a blend of the graft copolymer with a tackifying resin. Sheet materials can be coated with layers of the adhesive composition to provide tapes and laminates.

Description

WO 92/08765PCI/US9l/07849 -1~0 94~97 POLYOLEFIN PRESSURE-SENSITIVE ADHESIVE COMPOSITIONS
CONTAINING MACROMONOMERS

Technical Field 5This invention relates to pressure sensitive adhesive compositions comprising a copolymer with a saturated hydrocarbon backbone having one or more grafted pendant moieties preferably derived from polymerizable ethenylareneand conjugated diene monomers and to sheet materials coated therewith.

10~ACKGROUND OF THE INVENTION
A continuing need in the pressure sensitive adhesive (PSA) art is achievement of a better control over various mechanical and process properties so that adhesives can be "tailor-made" for specific, highly demanding end-use applications such as pack~ging, medical, and masking tapes. These applications 15 require a proper balance of PSA p-o~ies, which varies with each of the different end-uses.
Pressure sensitive adhesive compositions suitable, for example, for use in adhesive tape must have a requisite fourfold balance of adhesion, cohesion, stretchiness and elasticity as disclosed by U.S. Patent No. Re 24,906. The desire to 2 0 maintain this balance of properties makes it e~llcl-,ely difficult to improve internal strength i.e., cohesiveness without sacrificing other desirable properties ancl destroying the overall pressure-sensitive nature of the adhesive system.
Among the earliest polymers to provide a reasonable balance of the properties required for satisfactory PSA performance were the natural and synthetic 2 5 rubbers. However, these PSAs had poor cohesive strength, especially at elevated tempelaturl s and poor aging plol,clLies, e.g. they oxidized easily.
Phase-separating/segregating (PS) block copolymers, like the styrene-butadiene-styrene KRATONTM rubbers, can be used to improve the cohesive strength and hot-melt processability of PSAs. However this class of PSAs still ha~

3 0 poor aging properties. The PS block copolymers contain end-blocks which are capable of forming phase-separated/segregated "glassy" domains that act as thermally reversible crosslinks providing cohesive strength when such block ~, i , .

copolymers are used ln pressure-sensitive adhesives. At high temperatures the glassy domains effectlvely "dlssolve" in the rubbery phase. When the polymer is cooled, the domains reform allowing recovery of the original physical and chemical properties. The reinforcing nature of phase-separation in polymers is described in more detail by D. Satas, "Handbook of Pressure-Sensitive Adhesive Technology", Van Norstrand Reinhold, NY, 1982, pp.220-223 and L.H. Sperllng, "Introduction to Physical Polymer Science", John Wiley & Sons, NY, 1986, pp. 111-116 & pp. 279-280.
With the advent of Ziegler-Natta (ZN) catalysts, the polymerization of a-olefins to polymers, some of which are naturally tacky and have PSA properties, became possible.
However, unmodifled a-olefln polymer PSAs generally have poor internal strength.
U.S. Patent No. 3,542,717 descrlbes laminating adhesives made from tackified mixtures of ZN copolymers derived from a-olefin monomers of from 4 to 20 carbon atoms.
When tackified, the copolymer mixture has PSA properties, while certain other composltions functloned as hot-melt adhesives, see column 4, lines 22-34. While the cohesive strength of the adheslve was acceptable for its intended laminating applications, nothlng is mentioned about shear strength at elevated temperature.
U.S. Patent No. 3,954,697 discloses that PSAs provided by copolymers of polypropylene and C6 to C10 a-olefins can have good coheslve strength when hot-melt coated - ~a - 2094497 at a melt temperature of at least 350~F (177~C), a temperature at which the copolymers exhlblt no detectable crystalllnity when examlned uslng X-ray or DSC technlques.
U.S. Patent No. 4,178,272 dlscloses that a hot-melt adhesive that provldes strong T-peel and lap shear bonds can be made using a-olefln polymers. The hot-melt adheslve ls a blend of poly(propylene-co-hlgher l-olefln), tacklfylng resln, and crystalline polypropylene. The blend is not sald to be naturally tacky or a PSA. In Example 1, adheslve bonds are formed at 200~C.
The development of technlques of graft copolymerization, l.e. the attachment of hlgh molecular welght pendant slde chalns to the polymer backbone~

WO 92/08765 PCI'/US9l/07~49 3 ~0g4497 permitted modification of polymer properties. Most of this prior art does not deal with PSA systems.
U.S. Patent No. 4,007,311 shows that grafting methyl methacrylate to a styrene-isoprene-styrene block copolymer enhances adhesion without regard 5 for elasticity or cohesiveness.
U.S. Patent Nos. 4,554,324, 4,551,388 and 4,656,213 describe copolymers having macromonomers grafted to an acrylate polymer backbone by free-radical polymerization to improve the shear adhesion of pressure-sensitive adhesives and sheet m~tçri~lc coated therewith.
U.S. Patent No. 3,862,267 teaches how to make and use a number of vinyl terminated polystyrene macromonomers in copolymerization processe.s Witll other ethylenically unsaturated monomers. Tniti~tion of these copolymerizations is described as: addition, anionic, cationic, condensation, and coordination.

~ 1 5 SummarY Of The Invention Briefly, the present invention provides compositions that are PSAs at about 20~C to 30~C or become PSAs at higher temperatures comprising:
a) 40 to 99% by weight of a ZN graft copolymer comprising:
1) 0.1 to 25%, preferably 0.1 to 10% by weight of a 2 0 macromonomer comprising the polymerized product of at least one of an ethenylarene and a conjugated diene monomer and having a terminal cl~-alkenyl group of at least 4 carbon atoms and;
2) 99.9 to 75%, preferably 99.9 to 90% by weight of an alpha-olefin having 2 to 18 carbon atoms of which 60 to 100% of the total a-olefins are a-olefins having 6 to 14 carbon atoms;
and b) 60 to 1% by weight of one or more compatible tackifying resins.
In another aspect, the invention provides sheet materials coated with 3 0 the PSA composition. Such sheet m~tt-n~l.c comprise a backing member and thePSA coating composition of the invention covering at least a portion of one major surface thereof.

In stlll other aspects, the lnventlon provldes articles comprlslng the coated sheet material ln the conflguration of a roll of tape comprlslng a flexlble backing sheet having at least one major surface coated wlth the PSA of the invention. Another artlcle of the lnventlon ls a transfer tape comprising a fllm of PSA composition of the lnvention between two release liners.
In this applicatlon, the terminology and nomenclature relatlng to the macromonomers and graft copolymers of the lnventlon is that used by L.H. Sperling, "Introduction to Physlcal Polymer Sclence", John Wlley, NY, 1986, pp. 39-47, pp. 111-116, & pp. 279-280, "llvlng polymer" means a polymer prepared by anionlc polymerization that has no effectlve termination reactions ~Courle, "Polymers Chemlstry and Physlcs of Modern Materlals", Intex Ed. Pub., NY, 1973, p. 82-3);
"macromonomer" means a polymer havlng a number average molecular welght ranging from several hundred to tens of thousands, wlth a functlonal group -CH2-CH2-CH=CH2;
"at least one of an ethenylenearene and con~ugated dlene polymer" means a polymer prepared by anlonic polymerlzatlon that contalns either or both of ethenylarene and con~ugated diene unlts;
~Ziegler-Natta ~ZN) catalyst" means a two-component coordination inltlator or catalyst havlng the propertles descrlbed by Seymour and Carraher, "Polymer Chemistry", Marcel Dekker, Inc., NY ~1988), p. 296, and, X

-- 4a - 2094497 "llnear omega-alkenyl group" means a group havlng the formula -CnH2n-CH2-CH2-CH=CH2 where n ls 0 to 16;
~ alpha (a)olefln" means any vlnyl-contalnlng allphatlc monomer, and ln thls appllcatlon lncludes ethylene;
"number-average molecular welght (Mn)l welght average molecular welght (Mw) and Z-average molecular welght ~Mz)'' are well known mathematlcal descrlptlons of the molecular welght dlstrlbutlon of a polymer sample;
~ polydlsperslty (pp)" ls a measure of the molecular welght dlstrlbutlon of a polymer and ls deflned as MW~Mn.
Further explanatlon of the derlvatlon of these terms may be found ln Experlmental Methods ln Polymer Chemlstry, Wlley and Sons, 1981, Chapter 3 entltled "Molecular Welght Averages", pages 57-61.

WO 92/08765 2 4 PCI'/US91/07849 The adhesives of the present invention impart improved shear strength without crosslinking.
There is no prior art of which we are aware that discloses the use of chemically tailored, inherently tacky, macromonomer grafted, poly(a-olefin) 5 copolymers to make PSA compositions which possess improved shear strength.

DETAILED DESCRIPTION OF THE
PREFERRED EMBODIMENTS OF THE INVENTION
The graft copolymer of the invention is preferably phase-separatin~T
10 into rubbery and glassy domains that provide a PSA having a shear strength of at least 30 minutes, preferably from 75 to 10,000 minutes. It is further preferred that:
1) the rubber regions of the phase separated copolymer have a T8 in the range offrom -70~C to -10~C, 2) the glassy macromonomer rich domains have a Tg in the range of from 20~C to 300~C, and 3) the macromonomer has a number average molecular weight in the range of from 2,000 to 30,000. Peel adhesions of the PSAcomposition can be adjusted to pre-selected values by adding tackifying resins to the composition. The neat or tackified phase separating PSA compositions have excellent peel strength, shear strength, tack, creep resistance, and processability.
Furthermore, the adhesives have excellent thermal and thermo-oxidative stability2 0 because there are no residual ethylenically-unsaturated groups in the polymer backbone.
The phase separated domains of high Tg glassy macromonomer act as physical/reversible crosslinks interconnecting adjacent low T8 inherently tacky a-olefin regions. This dramatically increases the cohesive strength of the adhesive 25 and makes possible the formulation of high shear strength adhesives. The PSAs of the invention can be normally tacky at 20-30~C or they can become tacky upon application of heat.
Specifically, the graft copolymers of use in the tacky PSA
compositions of the invention are copolymers of (1) macromonomer comprising an 3 0 ethenylarene-conjugated diene polymer having a terminal omega-alkenyl group of at least 4 carbon atoms and (2) one or more alpha-olefin having 2 to 18 carbon atoms, preferably having the following formulae:

--(CH2-(~H)a(GH2C~b_ (CH2~CH)a(C~H2~b--2 t 7 1 2 R7 2 and 1 2 n) (~H2n) R(~3 p) Si(Ll-Z-R~)p ~;-R~
II

wherein:
L is a divalent llnking group selected from the group conslsting of o Rl R2 o in which each of R1 and R2 is independently hydrogen, an alkyl group having, 1 to 4 carbon atoms, phenyl, or both of R1 and R2 together with the carbon atoms to which they are attached form a ring having 5 or 6 carbon atoms; and most preferably, L
is a Rl R2 o Ll is a covalent bond or a dlvalent llnking group X

- 6a - 2094497 Rl R2 in which R1 and R2 are defined above;
R~ is a saturated or unsaturated linear hydrocarbyl group having 2 to 20 carbon atoms, a branched hydrocarbyl group having 3 to 20 carbon atoms or cyclic hydrocarbyl group having 5 to 20 carbon atoms;
R7 is hydrogen or one or more alkyl groups having 1 to 16 carbon atoms, at least 60% of R7 being an alkyl group having 4 to 12 carbon atoms;
n is an integer having a value from 0 to 16 preferably from 0 to 4;
p ls an integer having a value of 1, 2, or 3, W0 92/08765 PCI'/US9l/07849 2~94497 each R is independently a monovalent hydrocarbyl group which is selected from alkyl groups having from 1 to 18 carbon atoms, aryl groups having from 6 to 10 carbon atoms, and cyclic hydrocarbyl groups having from 5 to 10 carbon atoms, preferably, R is methyl or ethyl; and Z is a divalent polymeric group having either or both of polymerized ethenylarene and conjugated diene repeat units and preferably a number average molecular weight of from about 2,000 to about 30,000; and a and b are numbers providing a number average molecular weight of 50,000 to 10,000,000 to the graft copolymer, a having a value that is 0.1 to 25%
of (a + b), preferably 0.1 to 10% of (a + b) of one or both of 1) More particularly, Z is a divalent polymeric group obtained by the anionic polymerization of one or more of 1) at least one ethenylarene monomer having 8 to 20 carbon atoms, and 2) at least one conjugated diene monomer having4 to 20 carbon atoms.
The divalent polymeric group Z can be a homopolymeric group comprised solely of ethenylarene monomers, or solely of conjugated diene monomers. The polymer can also be a copolymer comprising both ethenylarene and conjugated diene monomers. The copolymer can be a random copolymer, a block copolymer, or a tapered block copolymer. When Z is a block polymeric 2 0 group, it may be di-block or higher. More preferably, Z has a number average molecular weight in the range of 2,000 to 30,000 and a polydispersity in the range of 1.05 to 5.0, preferably in the range of 1.05 to 3Ø
In preferred embodiments, the divalent polymeric Z group has the general formula:
Rl 4 IR5 I_ CH
tCH2-f=f-(~H)J(CH2-f)y(CH2~CIH~z - ~PLACEM13NT PAG~ 8 -20q4497 wherein s e~ch ~3, R' and Rs is independensly, hy~rogen, a phenyl ~roup, an alkyl group or alkenyl group havin~ 1 to 12 car~on a~ms [the~e being no more th~n 16 earbon atoms tot~l in (R.3 ~ R~)~, or any two of R3, ~, and R5 t~gether wilh ~hecarbon atoms to which t~lcy are a~che~l form one or two saturated or unsaturated5 or 6 carbon atom rings, preferably each of R3, ~ and Rs is hydrogen or me~yl; -- -R6 is an aryl group havin~ 6 to 18 carbon atoms, ~ptionally subst;tute~ by lower alkyl groups having from 1 so 4 carbon atoms, trialkysilyl, 2,~-dialkylallcoxysilyl, N,N-bis(trimethylsilyl)amino, kimethylsiloxyethyl groups; and 1,1-dimcthylcthoxycarbonyl; and x, y, and z are numbers providin~ a number averagc molccular weight of 2,000 to 30,000 to the polymcric Z group and e~pressing Ihe number of eshenylarene and conjugated ~ nc groups that are prcscnt ln random or bloc~c configuration In the polymeric Z gr~up, ;n which numbers any of x, y, and z can be z~ro, but at least onc of x, y, and z is not zcro.
The m~rom~nomers are p~drc~ by cithcr of methods I and II.
zo By method Ia, the macrolnon~l,.er is made by anionical1y polymerizing ethenylarene andlor con~u~a~ed diene mon~".~ form a living polymcr, thc Z
group ani~n, Md term~natlng the livin~ anion with a ~rm;nq~ g agent having multiple funct~onality, e.g. an omega-alkeny1 group and one o~ morc ~roup(s) capabl~ of undergoing nucleophilic displacement reactions. Useful termin~ting 2 5 agents include omega-alkenyl acid halides (as shown in Summary ~eactions I
below).
By meth~d Ib, ome~a-alkenyl mono, di-, and tA-, halosilanes whose highly reactive silicon-halogen bond allows controlled preparation of lincar, branclled and star macrom~notners having nar~ow molec~lar weight distribuLions are used as termlnating a~ents in thc prcpara~ion of thc macromonomcr (as shown in Summary ~eactions II below).
By method II~ the macromonomer is p~pared directly by reacting an initiator containing omega-alken~l groups with anionically polymerizable 9 ~9449~

ethenylarene and/or conjugated diene based monomers to form a living polymer and terminating the living anion by reaction with alcohol as is well known in the art. The polymerization and termination reactions are summarized in Summary Reactions III, below. The macromonomers of use in the adhesive compositions of 5 the invention have a glass transition temperature in the range of -70~ to above 100~C.

- REP~A~EMENT P~GE 10 -SU~A~Y ~EAC~IONS I
Method Ia 3~;.minntlon T~r~s A
Q C) R~~ C1~12~CHCnH2nCH2CH2CX - ~ R~ZI~CnH~nCH2CHzCII~Cl~t2 + LIX
poly",arlc acld hallde tc,.,.lr~-'t~.~ aDent . .. ~"~.,.. oa~.. cr m~tal SBt~
~na polym~
(L ~f Fonnuh I Is ~r~ntion ~ry~ R

R~ZLI~ t ~ H ~ ROZ~H~ O Li~
~ p~l~r.,~o alkoxy soll alkyl~nc oxido CH2~C HCnl~2nCH2C~2~X
R1 ~,2 Q acldh~lld~c.~ r~cll~aa~n~
~L of Fo~nul~ I Is--CH~HO~ ) v R~Z(~ H~lo~cH2cH2cnH2ncH=cH2 ~ LIX

r~.n~ .n~nGI~cl wherein R~~ Z, Rl, R2~ n~ ~nd X a~e 88 prev~ou~y def in~d .

- REPLACEM~;NT P~GE 11 -SI~IARY REAC~:ON~
Method Ib T~rn~ihAtlor~ Typ~ C
p (R~Z~ XpR~3 f,)SICnt~2nCH2CH2CH~H2 \
li~'n~ polymer ~ sr,JII,-~-sll~ ,o tonnlnal~ ~a ~nt ~R~Z~p~3.p~51CnH2nCi*CH2CH~Ci 12 ~ p LIX
n - . ~no,r~r cont~ln~n~ o 5tlyl tlnkin~ ~roup ~inAti~n T~e D

p (R Zi i ) ~ ~H /~ p (R~Z~H~OLI~) ~O R~Zalkoxy anion n~ polymor alkylonooxlde ~
~ Xp~3 p)$lcn~2ncH2cH~cHecl~2 R1 ~2alkonylhalosilaneterrnlnatln~aoont (iR~i!lH~:HO)pR~.p~Si~ni;~nC---i2Cl~i2CHsC~2 t p LIX
n~ - r.~nG.,.~rcornalnln~ 5110xy llnkln~ ~roup where~n R~~ Z~ R~ n, and X ar~ ~s previously defined .

Summary React ions III
Method II

H2C-CHCH2CH2C2H2n-Li + H2C- lC- (~;CH and/~ H2C- I

all~nyl lithium mitia~ conjugated diene edlenylarene H2C~CHCH2cnH2n~z~~
liv~ng 1101,~

alc~ol H2C=CHCH2CH2CnH2n~z~H

co~dina~ botld linl~ng agent .h~in R3, R4, R5, R6, Z, and n are a~ previou~l deR ~

If a less reactlve anion is desired in either of Methods Ia or Ib, the living polymer anion can be converted to an alkoxy anion by the addition of ethylene oxide or substituted ethylene oxide prior to reaction wlth the terminating agent (Termination Types B and D).
The anlonic polymerization methods used to make the Z group anion are well known to those skllled ln the polymer art. Such methods are discussed by Seymour and Carraher, supra, p. 291-296. For example, the Z groups can be conveniently prepared by reactlng at least one of ethenylarene k-2~94497 - 12a -and coniugated dlene monomers with an alkali metal hydrocarbon or alkoxlde salt in the presence of an lnert hydrocarbon or ether organlc solvent that does not participate in, or interfere with, the polymerlzatlon process. Anlonic polymerlzation methods are also described by Milkovlch at al., (U.S. Patent Nos. 3,786,116 and 3,842,059).
The dlvalent polymeric group, Z, can be a homopolymeric group made from only ethenylarene monomers, or only from coniugated diene monomer. It also can be random or block polymeric group formed from both ethenylarene WO 92/08765 PCr/US91/07849 -132~ 7 and conjugated diene monomers. When Z is a block polymeric group it may be di-block or higher.
Preferably, the macromonomer has a number average molecular weight in the range of 2,000 to 30,000. Although U.S. Patent No. 3,786,116 teaches that the molecular weight distribution of the polymer chains of a macromonomer should be narrow, i.e., a polydispersity of less than 1.1 for preparation of polymer having improved physical characteristics useful as tough,flexible self-supporting films, it has been found that useful PSA compositions according to the present invention can be made with macromonomer having a 1 0 polydispersity of up to about 5 without deleterious effects on adhesive properties.
The polydispersity of the macromonomer of the invention preferably can be from about 1.05 to 5.0, preferably 1.05 to 3Ø
Any ethenylarene having 8 to about 20 carbon atoms that can be polymerized by anionic polymerization methods can be used in the preparation of the divalent Z group. Examples include: styrene(ethenyl benzene), a-methylstyrene (propenylbenzene), 1-ethenyl-2-methylbenzene, 1-ethenyl-3-methylbenzene, 1-ethenyl-4-methylbenzene, 1-ethenyl-4-(1,1-dimethylethyl)benzene, 4-dodecyl-1-ethenylbenzene, l-ethenylnaphthalene, 2-ethenylanthracene, 10-ethenylanthracene, 1-ethenylfluorene, 2-ethenylphenanthrene, 1-ethenylpyrene,2 0 and the like. Examples of ethenylarenes substituted by groups that provide elevated glass temperatures to the macromonomers of use in the invention and areunreactive under anionic polymerization conditions are:
1-ethenyl-4-methylbenzene, 1-ethenyl-4-ethylbenzene, 1-ethenyl-4-t-butylbenzene,1-ethenyl-4-(trimethylsilyl)benzene, 1-ethenyl-4-(dimethyl-1-methylethoxysilyl)benzene, 1-ethenyl-4-[N,N-bis(trimethylsilyl)amino]benzene, 1-ethenyl-4[1,1-dimethyl)ethoxycarbonyl]benzene, and the like.
Any conjugated diene having 4 to about 20 carbon atoms capable of polymerization by anionic methods can be used in the preparation of the monovalent polymeric Z group. Examples of linear and branched conjugated dienes include: 1,3-butadiene, 1,3-pentadiene, 1,3-hexadiene, 1,3-heptadiene, 2-methyl-1,3-butadiene (isoprene), 2,3-dimethyl-1,3-butadiene, 2,3-diethyl-1,3-butadiene, 2,5-dimethyl-1,3-hexadiene, 2-phenyl-1,3-butadiene, 2,3-diphenyl-1,3-- REPLACEMEN r PAG~ 14 -5 butadiesle, 2-methyl-6-methylene-2,7-octadlene(myrcenc), and the li~e. Examples oî cyclic conju~ated dienes lnclude: 1,2-bis(methylenc~cyclopentane, 1,2-bis(methylcnc)cy~lohexane, 3-melllylenecyclohe~sne, 1-ethenylcyclollcxene, 1-e~henylcycl~pentene, 2,3-bis(methylene)bicyclo[2.2.1~heptane, and the like.
Ini~iators for anionic polymer~zation may be ~ny of the alkali metal ---o hydrocarbyl salts which produce a monofuncdonal living polymer, i e, only one end of the polymeI cont~ns a reacti~e ion Such initi~tors include or~anometallichydrocarbon s~lls lithium, sodium, or potasslum, ~or example, having an alXyl oralkenyl radical containing up ~o 20 carbon atoms ~ more, and preferably ~p to 8 carbon atoms, Illuskative al~ali metal or~anometallic in;ti~t~rs include ~5 e~hylsodi~lm, propylsodium, phenylsodlum, ethyllithium, propyllithium, n-butyllithium, i-butylllthlum, tert-butyllithium, 3-butenyllithium, 4-penteny}lithium, 5-hexenyllilhium and 7-vctenyllithium, The prefer~ed lnltiators are n-butyllithium, sec-butyllithium, and 3-bulenyllith;~
~erminatin~ a~cnts for use in Method I, Terminatin~ Types ~ and B may 20 be chosen from ~-alkenoyl halides cont~lnil~ 5 to 18 carbon atoms, preferably 5 to 10 carbon atoms, tllere beillg al le~t 2 carbon atoms between ~he carbonyl group and the omega double bond. Illustrative allcenoyl chloride~ include 5-hexelloyl chlvnde, 6-heptenoyl chlonde, 7-octenoyl chlodde, 9-decenoyl chloride,10-undecenoyl chloride, 13-tetradecenoyl chloride, and 17-octadecenoyl chloride.2s The more preferred alkenoyl chlorides are 5-hexenoyl e~lori(le and 10-unde~enoyl chloride.
Tcrminating agents for use in Method T, Terminati~n Typ&s C and D may be chosen from omega-allcenylh~l~c~ es conlaining up to 18 methylene groups, preferably 4 or morc m¢thylene g,roups, which are cvn"l~e,eially available (see ~) 3 0 or call be mad~ using the methods disclosed in the ~xamples (infra). Illustrative ~-all;enylhalosilancs inclu~e, for e~ple:

WO 92/08765 PCI'/US91/07849 -~9~97 3-butenyldimethylchlorosilane 5-hexenyldimethylchlorosilane*
7-octenyldimethylchlorosilane*
2-methyl-5-hexenyl~lim~thylchlorosilane 5 17-octadecenyldimethylchlorosilane 5 -hexenylmethylphenylbromosilane 5-hexenyldiphenylchlorosilane 3-butenylmethydichlorosilane 7-octenylmethyldibromosilane 1 0 5-hexenyltrichlorosilane*
7-octenyltrichlorosilane*
*These aL~enylchlorosilanes are available from Petrarch Systems, Bristol, PA
19007.
Since every Method II initiator molecule contains an alkenyl group, 15 every resulting living polymer anion contains an alkenyl group; therefore, unlike Method I macromonomers, the efficiency and yield of the termination reaction by Method II does not affect the conversion of living polymer to macromonomer.
Graft copolymPri7~tinn of the a-olefin and the macromonomer according to the present invention are conducted using a ZN coordination catalyst.
2 0 Such ZN coordination catalyst systems are described by Seymour and Carraher, Supra. The preferred 2-component catalyst systems are diaLkyl aluminum chloride/titanium trichloride or diaLIcyl alu~ u--- sesquichloride/vanadium oxytrichloride. Reaction takes place in the presence of inert solvents in the temperature range of about -100~C to abut +100~C. Suitable nonpolar organic 2 5 reaction solvents include heptane, toluene, hexane, cyclohexane, pentane, and the like. The amount of solvent is generally about 10 to 30% by weight based on the total weight of the reactants and solvent.
Furthermore, about 1.5 to 8 moles excess Lewis acid such as (GH5)3Al, AlC13, SnC14, or BC13, can be used with macromonomers containing 3 0 carbonyl linking groups to shield the carbonyl group from interaction witll the ZN
catalyst during the graft copolymerization process.

As described above, the preferred graft copolymer ls prepared by copolymerlzatlon of a-olefin and reinforcing (see Summary Reactlons I, Method Ia, type B above) macromonomer.
The graft copolymer, however, can be prepared by techniques which provide a degree of predictability of the propertles of the end products. These and other polymer graftlng techniques are described by Noshay and McGrath in Block Copolymers, Academic Press, New York (1977), pages 13-16.
A substantial increase ln shear strength results when macromonomer ls copolymerized with a-olefin. The amount of macromonomer in the copolymer determlnes the shear propertles of the copolymer. Wlth increaslng amounts of macromonomer the resultant copolymer becomes lncreaslngly less tacky. However, these materials are useful as hot-tackifylng, heat actlvated, or semi structural adheslves.
The a-olefins of the ZN graft copolymer of the PSA
composition have the following formula:
CH2=CH-R7 wherein R7 is as previously defined.
Preferred a-olefin comonomers include, but are not limited to, linear C6 to C14 a-olefins such as l-hexene, l-octene, l-decene, l-dodecene, l-tetradecene and the like;
and branched a-olefins such as 2-methylbutene, 3-methylhexene, 8-methyldecene, 10-methyldodecene, and the like. Alpha-olefins such as ethylene, propylene, l-butylene, isobutylene, and l-pentylene can be used.
In addition to the macromonomer-containing a-olefin X

- 17 - 20944~7 polymers, the PSA composltion of the lnventlon contalns a tacklfylng resln whlch lmparts tack, lower vlscoslty, lmproved coatabllity, good heat stablllty, and improved peel adhesion.
Compatlble tacklfylng resln can be prepared by polymerlzatlon of monomers consistlng primarily of oleflns and dloleflns and lnclude, for example, residual byproduct monomers of the lsoprene manufacturlng process. These hydrocarbon tackifylng resins typlcally exhlblt Ball and Rlng softenlng polnts of from about 80~C to about 145~C; acld numbers from about 0 to 2, and saponlflcation values of less than one. Examples of such commercially available tacklfylng reslns based on a C5 olefin fraction of this type are "Wingtack"* 95 and "Wingtack"
115 tacklfylng resins available from Goodyear Tire Rubber Co.
Other useful hydrocarbon tacklfylng reslns lnclude "Regalrez"* 1078 and "Regalrez" 1126 tackifying resins available from Hercules Chemical Co., Inc. Wilmington, DE; Arkon~ resins, such as Arkon~ P115, avallable from Arakawa Forest Chemical Industries, Chicago, IL; and Escorez~ resins available from Exxon Chemlcal Co.
Other sultable tacklfylnq reslns include the terpene polymers, such as polymeric resinous materials obtained by polymerization and/or copolymerization of terpene hydrocarbons such as allcycllc, mono and blcyclic monoterpenes and their mixtures including carene, isomerlzed pinene, terpentene, and various other terpenes. Commercially available resins of the terpene type lnclude the Zonarez~ terpene * Trademark - 17a -B-series and 7000 serles avallable from Arizona Chemlcal Corp., Wayne; NJ 07470. Typical propertles reported for the Zonarez~ terpene reslns lnclude Ball and Rlng softenlng points of about 55~C to lZ5~C (ASTM E28-67), Acld Numbers of less than one (ASTM D465-59), and Saponlflcatlon Numbers of less than one (ASTM D464-59). The terpene resin used in Examples below is a poly(beta-pinene) resln, Plccolyte~ S115 resin, available from Hercules Chemical Co., Inc., which has a Ball and Rlng Softenlng Polnt of 115~C, an Acld Number of one, and Iodlne Number of 190.
The tacklfying reslns may contain ethylenlc unsaturatlon; however, saturated tacklfying resins are preferred for those appllcatlons where oxldation resistance ls important. The total amount of tacklfylng reslns ln the composition ls 1 to 150 parts, more preferably 5 to 50 parts, and most preferably 15 to 35 parts by welght per 100 parts of polymer. Incompatible tacklflers such as those based on rosin esters are not useful ln the practlce of the lnventlon slnce they produce hazy blends. Furthermore, the presence of the lncompatible tacklfier results ln a loss of tack.
Minor amounts of additives can also be lncluded ln the composltion to provide adheslves for special end uses.
Such addltlves may include pigments, dyes, plastlclzers, fillers, stabilizers, ultraviolet absorbers, anti-oxidants, and the like. Plasticizers which can be employed include the well-known extender oils (aromatic, parafflnic, or napthanic) as well as wlde variety of llquld polymers.

WO 92/08765 x~ PCI /US9l/07849 Amount of additives used can vary from 0.1 to 50 weight percent dependin~ on theend use desired.
The adhesive composition of the present invention can be coated onto a wide range of substrate m~teri~l.c, some examples being polymer films such as polyethylene terephthalate [PET], and biaxially oriented polypropylene [BOPP];
woven and non-woven fabrics; metals including metal foils such as aluminum, copper, lead, gold and the like; paper; glass; ceramics; and composite materialscomprised of laminates of one or more of these materials.
The present invention copolymers are useful to prepare PSA tapes and coated articles. Coating can be accomplished by methods known in the art on the desired substrates (representative substrates are mentioned above). Coatingshaving thicknesses in the range of 5 to 250 micrometers can be useful. When flexible substrates are used, the resulting tapes can be wound into rolls. For PSA
tapes and transfer tapes it may be desirable to use primer and low adhesion backsize layers, or to inteIpose one or more release liners in the roll. Sheet stock such as labels and decals can also include at least one of a primer layer, a lowadhesion b~ck~i7e layer, and a releae liner.

TEST METHODS
2 0 The test methods used to evaluate the PSA coated flexible sheetm~teri~ls are industry standard tests. The standard tests are described in detail in various publications of the American Society for Testing and Materials (ASTM).
Phil~-lelphia, PA. and the Pressure Sensitive Council (PSTC), Glenview Ill. The standard test methods are described in detail below. The reference source of each 2 5 of the standard test methods is also given.

SHEAR STRENGTH
(REFERENCE: ASTM D3654-78; PSTC-7) The shear strength is a measure of the cohesiveness or internal 3 0 strength of an adhesive. It is based upon the amount of force required to pull an adhesive strip from a standard flat surface in a direction parallel to the surface to which it has been affixed with a definite pressure. It is measured in units of time -19- 2~9~7 (minutes) required to pull a standard area of PSA coated sheet material from a stainless steel test panel under stress of a constant, standard load.
The tests are conducted on adhesive coated strips applied to a stainless steel panel such that a 12.7 mm by 12.7 mm portion of each Stlip is infirm contact with the panel with one end portion of the tape being free. The panel with coated strip attached is held in a rack such that the exposed face of the backing of the strip forms an angle of 182~ at the edge of the panel when a massof one kilogram is applied as a hanging weight from the free end of the coated strip. The 2~ greater than 180~ is used to negate any peel forces, thus ensurin~ that only the shear forces are measured, to determine the holding power of the tape being tested. The time elapsed for each tape example to separate from the test panel is recorded as the shear strength.
The time at which the mass falls at room temperature is called "RT
Shear" (average of two specimens). When reported as "1000+", the tape had not failed after 1000 minutes. When the RT Shear is below about 30 minutes, the adhesive of the tape has generally failed by "pop off".

PEEL ADHESION
(REFERENCE: ASTM D-3330-78 PSTC-1(11/75) 2 0 Peel adhesion is the force required to remove a coated flexible sheet material from a test panel measured at a specific angle and rate of removal. In the examples, this force is expressed in Newtons per 100 mm (N/l00 mm) width of coated sheet. The procedure followed is:
1. A test specimen 12.7 mm wide is applied to a horizontally 2 5 positioned clean glass test plate. A 2.2 Kg rubber roller is used to press a 12.7 cm length of specimen into firm contact with the glass surface.
2. The free end of the coated strip is doubled back nearly touchin~
itself so that the angle of removal will be 180. The free end is 3 0 attached to the adhesion tester scale.

WO 92/08765 ~ PCI/US9l/07849 ,~9 -2 0 -3. The glass test plate is clamped in the jaws of a tensile testing machine which is capable of moving the plate away from the scale at a constant rate of 2.3 meters per minute.
4. The scale reading in Newtons is recorded as the tape is peeled from the glass surface. The data is reported as the range of numbers observed during the test.
Compatibilities of various base polymers with the tackifying resins and the plasticizers are determined by melting the samples of each blend betweenglass plates and observing the clarity of blends.
MOLECULAR WEIGHT
Number average molecular weight of the macromonomer is determined by the initiator/monomer ratio and the amount of initiator may vary from about 0.00l to about 0.l per mole of monomer, or higher. Preferably~ the concentration of the initi~tc)r will be from about 0.002 to about 0.04 mole initiator per mole of monomer. The smaller the initiator/monomer ratio the higher the number average molecular weight.

INHERENT VISCOSITY MEASUREMENT
2 0 In order to understand the benefits derived from the teachings of this invention, it is necessary to relate the improvements in shear strength and processability to the molecular weight of the adhesive and of the polymeric monomer which is incorporated into the adhesive. It is the comparative values which are significant and absolute figures are not required.
2 5 The inherent viscosity is measured by conventional means using aCannon-Fenske #50 viscometer in a water bath controlled at 25~C to measure the flow time of l0 ml of a polymer solution (0.2 g of polymer per deciliter in hexane). The Examples and Comparative Examples were run under identical conditions.

WO 92/08765 PCI'/US9l/07849 -21- 21~94~?

GEL PERMEATION CHROMATOGRAPHY
The characterization of the molecular weight distribution of the polymeric monomers was carried out by conventional gel permeation chromatography (GPC).
A Hewlett-Packard Model 1084B high performance liquid chromatograph equipped with six (6) ultra STYRAGEL RTM columns of sized 106A, 105A, 104A, 103A, 500A and 100A was used for all determinations. Samples were dissolved in toluene and filtered through a 0.5 micrometer polytetrafluoroethylene filter. Samples were injected at volumes of 170 yl to 200 ,ul and eluted at a rate of 1 ml per minute through the columns maintained at 40~C.
Toluene was used as a solvent. The differential refractometer detector was a Hewlett-Packard Model 79877A. The system was calibrated using polystyrene standards and employing the least squares fit. All GPC calculations were performed on a Hewlett Packard Model 3388 integrator and all molecular 1 5 weights averages are polystyrene equivalent molecular weights. The molecular weight averages and polydispersities were calculated according to standard procedures. GPC test methods are further explained in "Modern Size Exclusion Liquid Chromatography" Practical Gel Permeation Chromatography, John Wiley and Sons, 1979.
EXAMPLES
The following detailed description includes examples of preparation of macromonomers, ZN graft copolymerization with C6 to C,0 a-olefins to form graft copolymers, and formulation of pressure sensitive adhesive compositions 2 5 made by blending the graft copolymers with tackifying resins. All parts in the examples are by weight unless otherwise specified.

WO 92/08765 ~ PCl'/US9l/07849 PREPARATION OF MACROMONOMERS
Method Ia, Termination Type C(a) (Macromonomer having a carbonyl linking group and a polystyrene homopolymeric Z group) A l0-undecenoyl-terminated polystyrene polymeric monomer having an average molecular weight of about 10,000 was pl~parcd. A l-liter, four-neckedflask, fitted with a thermometer, mechanical stirrer, septum, Dean-Stark trap and condenser was charged with 500g reagent grade toluene and heated therein tO
reflux under a slow argon stream. A portion (150 g) of the toluene was removed through the trap to eliminate water from the system, leaving 350g (approximately400 mL) of toluene.
Styrene monomer was first purified by passing over 200 mesh silica gel under argon and then 30 g (288 mmole) of this styrene monomer was introduced into the reaction flask by syringe through the septum to produce 8% by weight of the solution of styrene monomer in toluene. The solution was maintained at 60~C. About 5 to 10 drops of a 1.4 M solution of n-butyllithium inhexane was added dropwise to the monomer solution until a faint yellow color persisted, indicating completion of the reaction with the impurities. Then 2.2 mL
of the solution was added rapidly, causing an exothermic reaction. The flas~
2 0 contents were maintained at 60~C.
The rate of consumption of the monomer was followed by gas chromatography. The reaction was essentially completed in 1 hour. The reaction was run an additional 2 hours to ensure the complete conversion of the monomer to the polymer. The contents were cooled to 35~C. Ethylene oxide gas was introduced over the reaction mixture and the solution was rapidly agitated for 15 minutes until the orange color the polystyryllithium had completely disappeared.The reaction was then quenched with 2.5 grams of 10-undecenoyl chloride. The reaction mixture was stirred for an additional 2 hours at room temperature. Tlleresultant polymer solution was then reduced in volume to approximately one-tllird 3 0 and added dropwise to a large excess of isopropanol. The precipitated polymer was collected on a large sintered funnel, dried overnight under ambient conditions, further dried at 65~C for 24 hours in a forced air oven and finally completely dried W092/08765 -23- 2~

in vacuo. It was designated MAC-3b. Gel permeation chromatography revealed a number average molecular weight (Mn) of 10,050, a weight average molecular weight (Mw) of 13,270. Its polydispersity was 1.32. Analysis confirmed that the formula was essentially:

HgC4~CH2~CH ~6CH2~CH2~0C~CH ~ CH=CH2 Method Ib, Termination Type D
(Macromonomer having a polystyrene homopolymeric Z group and a silyl linking group) A 5-hexenyldimethylsilyl-terminated polystyrene polymeric monomer having an average molecular weight of about 10,000 was prepared. An oven dried S00 mL two necked flask equipped with a magnetic stirring bar, condenser and a septum, was purged with dry argon and was charged with 10 g (96 mmole) of styrene in 200 g of toluene (5% by weight of solution). The solution was heated to about 60~C and 1.4 M solution of n-butyllithium in hexane was added dropwise 15 until a faint yellow color persisted, then O.SS ml of additional n-butyllithium in hexane solution was added rapidly. The reaction I~ Ult~ was maintained at 60~C
throughout the course of the reaction. The progress of the reaction was monitored by gas chromatography. The reaction was essentially completed in 1 hour. The reaction was run an additional 2 hours. The reaction mixture was cooled to 35~C
2 0 and then O.SS grams (a 3 fold molar excess) S-hexenyldimethylchlorosilane was added to quench the reaction. The polymer solution was reduced in volume and the polymer was precipitated and dried as described for Macromonomer MAC-3b.
Gel permeation chromatography revealed a number average molecular weight of 10,200 weight average molecular weight 12,850 and polydispersity of 1.2. The 2 5 macromonomer was designated MAC-6c. Analysis confirmed that the formula was essentially:

WO 92/08765 ~ -24- PCI/US91/07849 HgC4~cH2-f H ~s i-C2H4- CH2CH2 -CH=CH2 ¢~ CH3 Method Ia, Termination TYPe B
(Polystyrene homopolymeric Z group, coordinate bond linking group) The procedure used to prepare MAC-6c was repeated except that the living polystyryl anion was terminated with S-hexenyl chloride. The macromonomer obtained had Mn = 10.500 and a polydispersity of 1.2. It was designated MAC-22. Analysis confirmed that its structure was essentially:

Hgc4~cH2-f H t~8C2H4-CH2CH2-CH=CH2 Method Ib, Termination Type D
(Polystyrene homopolymeric Z group, and a silyl linking group) The procedure used to prepare MAC-6c was repeated using 4-t-butylstyrene in place of styrene. The macromonomer obtained had Mn = 13,000 and a polydispersity of 1.18. It was design~ted MAC-10.
Analysis confirmed that its structure was essentially:

W0 92/08765 2Q9 ~ ~ 7 Cl/US91/07849 HgC4tCH2-CHtj~ i-C4H~-CH2CH2-CH=CH2 ~ CH3 Method II, Butenyl initiatin~ ~roup, alcohol quench (Macromonomer having polystyrene homopolymeric Z group) A 3-butenyl-terminated polystyrene macromonomer having an average molecular weight of about 12,000 was prepared. Styrene (15 g, 144 mmole) was added to 200 g of cyclohexane under anhydrous conditions in the reaction flask producing 7.5 weight percent solution of monomer in the solvent.
Approximately 5 to 10 drops of 0.07 molar solution of 3-butenyllithium in hexanewere added to the monomer solution to remove impurities and then 19.7 mL of the 3-butenyllithium were rapidly added at 0-5~C. The temperature of the reaction was slowly raised to 60~C and maintained at that temperature throughout the course of the reaction. Living polystyryl lithium anion formation was slower with this catalyst than with secbutyllithium. Progress of the reaction was monitored by gas chromatography. The styrene monomer consumption was complete in about 3 hours. The reaction was run for an additional 18 hours. The reaction was quenched with excess methanol. The solution volume was reduced and added as described above to methanol to precipitate the polymer which was collected, dried and designated MAC-20a. Analytical results were as follows: M" = 11,570 and M~, = 14,576 and polydispersity of 1.25. Analysis confirmed that the 2 0 macromonomer has a structure that was essentially:
HtCH~troCH2cH2CH=CH2 W092/08765 ~ -26- PCI/U591/07N49 PREPARATION OF GRAFT COPOLYMERS
The data of Examples 1 to 32 is provided in TABLE I, below.

Examp]e 1 Five grams of macromonomer-3b (see Table I, below) was dissolved in 20 g of toluene in a dry two-necked flask covered with rubber septa and fitted with an inlet and outlet for an argon purge. One ml of (1.8 M) diethylaluminum chloride in toluene was injected by syringe through the septum into the macromonomer solution to form a Lewis acid complex comprised of the macromonomer and the Group III metal portion of the ZN catalyst. In a dry kettleequipped with stirrer and argon purge, 95 grams of the 1-hexene monomer was dissolved 480 g of dry toluene. The macromonomer solution was cannulated under argon to the kettle, and polymerization initi~tecl by adding the ZN catalyst consisting of 1.0 ml of 1.8 M diethylaluminum chloride and 0.11 g of AATiCI3 (aluminum activated reduced titanium trichloride, available from Stauffer Chemical Co., Inc., Westport, CN) having a Al:Ti mole ratio of 6:1. Polymerization proceeded with a slight exotherm. After 3 hours, the catalyst was deactivated and the ~raft copolymer was precipitated by the additional 3 liters of methanol. Thepowdery, precipitated copolymer was washed with methanol to remove spent 2 0 catalyst and unreacted monomers. The copolymers were stabilized by addingIrganoxTM 1010 antioxidant (available from Ciba-Geigy), (3.25% by weight) and dried in a vacuum oven at 60-70~C to constant weight. (72 perçent conversion).

Examples 2-5 2 5 Using the method of Example 1, the PSA composition shown in TABLE I, designated Ex. 2-5, all of which include a tackifier were prepared. Thetackifier was added after preparation of the copolymer to yield the PSA
composition.

WO 92/08765 PCI'/US91/07849 Example 6 The procedure in Example 1 was repeated except that 95 g of l-octene and 5 g of MAC-3b were used to prepare the copolymer. The copolymer was obtained in 85 percent conversion.

Examples 7-12 The procedure and components of Example 6 were used except that a tackifier was added to the copolymer.

Example 13 A solution containing 95 g of l-hexene and 5 g of MAC-22 and 100 g of toluene was charged to the reactor (flame dried under argon) fitted with stirrer, argon inlet and outlet, and a condenser. To the solution, the required amount of diethylalumium chloride and AATiCl3 was added. The molar ratio of Al to Ti was 2.5 to 1. The copolymerization was allowed to proceed for 6 ho~lrs at 25~C. The resulting copolymer was isolated by precipitation in excess methanol (78 percent conversion).

Examples 14-15 2 0 The procedure and components of Example 13 were used except a tackifier was added to the copolymer.

Example 16 The procedure in Example 13 was repeated except that 95 g of 2 5 l-hexene and 5 g of MAC-6c were used to prepare the copolymer. The copolymer was obtained in 72 percent conversion.

Examples 17-20 The procedure and components of Example 16 were used except a 3 0 tackifier was added to the copolymer.

W O 92/08765 ~9 ~ PC~r/US91/07849 ~ 28-Example 21 The procedure in Example 13 was repeated except that 95g of 1-octene and Sg of MAC-6c were used to prepare the copolymer. The copolymer was obtained in 56 percent conversion.

Examples 22-23 The procedure and components of Example 21 were used except a tackifier was added to the copolymer.

1 0 Example 24 The procedure in Example 13 was repeated except that 85 g of 1-hexene and lS g of MAC-10 were used to prepare the copolymer. The copolymer was obtained in 65 percent conversion.

Example 25 The procedure and components of Example 24 were used except a tackifier was added to the copolymer.

Examples 26 The procedure in Example 13 was repeated except that 95 g of 1-octene and 5 g of MAC-20a were used to prepare the copolymer. The copolymer was obtained in 66 percent conversion.

Examples 27-28 The procedure and components of Example 25 were used except a tackifier was added to the copolymer.

Example 29 The procedure in Example 13 was repeated except that 95 g of 3 0 1-hexene and 5 g of MAC-20a were used to prepare the copolymer. The copolymer was obtained in 56 percent conversion.

WO 92/08765 PCI/US9l/07849 -292094 ~ ~

Examples 30-32 The procedure and components of Example 29 were used except that a tackifier was added to the copolymer.

PREPARATION OF PRESSURE-SENSlTIVE ADHESIVE TAPES
Pressure-sensitive adhesive compositions were prepared from the macromonomer containing graft copolymers by blending the indicated quantity of tackifying resin with 100 parts by weight graft copolymer. Sufficient toluene was added to form a solution with a viscosity suitable for knife coating (5-15% solids) 1 0 to produce a coating thickness of 25-ym of dry coating. Each adhesive composition was knife coated onto 38-ym biaxially oriented poly(ethylene-terephthlate) film. The coating was dried for 5 minutes at 150~F (65~C) and conditioned for 24 hours at 90% relative humidity and 90~F (37~C) to prepare PSAtapes suitable for testing. The t~ckifiers used in the PSA formulations were:
1 5 "Wingtack Plus"
"Regalrez 1126"
"Arkon P115"
Tape testing was carried out according to the test methods previously described, and the results are shown in TABLE I. It is to be observed2 0 in TABLE I that improved R.T. Shear is to be obtained generally with increasing amount of tackifier for each of the dirre~ tly termin~ted macromonomer-olefin graft copolymers and that certain t~ifiers are more efficient in improving R.T.
Shear than others for a given graft copolymer. Ex. 3 shows that, for example, 33%
Wingtack Plus in a MAC-3b-hexene copolymer provided a R.T. Shear of 10,000+
2 5 while 33% Wingtack Plus in a MAC-3b-octene the R.T. Shear was only 119 (Ex.7); for a composition having 33% Regalrez 1126 in a MAC-3b-octene the R.T.
Shear was 8,500+ (Ex. 9). The results show further that without any need for ~ chemical crosslinking, addition of tackifier resin to the macromonomer-olefin copolymer provided pressure sensitive adhesives with peel values of 30 to 80 N/dm 3 0 and with enhanced shear strength.

W O 92/08765 ~ PC~r/US91/07849 TABLE I

Ex. Macromonomer Olefin Tackifier Peel R.T.Sllear No. (Mn)(WP%)(p) (wt%) (phr) (N/dm)(Min) 1 * MAC-3b 1-hexene None 8 25 (10,050)(5)(1.32) (95) 2 - " " Wingtack 38 2,100 Plus (18) 3 " " Wingtack 5210,000 Plus (33) 4 " " Regalrez 72 8,220 1126(33) " " Arkon 67 9,800 P115(33) 6 * " 1-octene None 16 7 (95) 1 0 7 " " Wingtack 68 119 Plus (33) 8 " " Reglarez 53 159 1126(18) 9 " " Regalrez 80 8,500 1126(33) " " Regalrez 82 sh8,500 1126(54) 11 " " Regalrez 68 sh10,000+
1126(100) 12 " " Arkon 72 1,150 P115(33) 13 * MAC-22 1-hexene None 10 35 (10,500)(5)(1.2) (95) 14 " " Wingtack 58 6,500 plus (33) " " Arkon 62 5,000 P115 (33) 16* MAC-6c 1-hexene None 13 18 (10,200)(5)(1.26) (95) 2 0 17 " " Wingtack 621,575 Plus(33) W0 92/08765 3 1 ~ 9 ~

18 " " Regalrez 76 8,600+
1126(33) 19 " " Arkon 45 5,000+
P115(18) " " Arkon 68 3,500+
P115(33) 21* " l-octene None 17 105 (95) 22 " " Regalrez 75 1,549 1126(33) 23 " " Arkon 68 5,000+
P115(33) 24* MAC-10 l-hexene None 38 56 (13,000)(15)(1.18) (85) " " Wingtack 86 1,096 Plus(33) 26* MAC-20a l-octene None 18 15 (11,570)(5)(1.25) (95) 1 0 27 " " Regalrez 35 10,000+
1126(18) 28 " " Regalrez 74 13,000+
1126(33) 29* " l-hexene None 11 55 (95) " " Wingtack 72 67 plus (33) 31 " " Regalrez 74 678 1126(33) 32 " " Regalrez 65 sh1,500+
1126(54) * = COIT parative (free of tackifier) sh = shocky (doesn't peel smoothly) Various modifications and alterations of this invention will become 2 0 apparent to those skilled in the art without departing from the scope and spirit of this invention, and it should be understood that this invention is not to be unduly limited to the illustrative embodiments set forth herein.

Claims (10)

CLAIMS:

1. A pressure-sensitive adhesive composition comprising a mixture of:
a) 40-99% by weight of a ZN graft copolymer comprising 1) 0.1 to 25% by weight of a macromonomer comprising the polymerized product of at least one of an ethenylarene and a conjugated diene monomer, said product having a terminal .omega.-alkenyl group of at least 4 carbon atoms and;
2) 99.9 to 75% by weight of an alpha-olefin having 2 to 18 carbon atoms of which 60 to 100% of the total .alpha.-olefins are .alpha.-olefins having 6 to 14 carbon atoms; and b) 60-1 weight % of one or more tackifying resins.

2. The pressure-sensitive adhesive composition according to claim 1 wherein said graft copolymer contains units having at least one of the formulae:

and wherein n is an integer from 2 to 6;
L is a divalent linking group selected from the group consisting of and , in which each of R1 and R2 is independently hydrogen, an alkyl group having 1 to 4 carbon atoms, phenyl, or both of R1 and R2 together with the carbon atoms to which they are attached form a ring having 5 or 6 carbon atoms;
Z is a divalent polymeric group having either or both ethenylarene and conjugated diene repeat units;
R° is a saturated or unsaturated linear, branched or cyclic hydrocarbyl group having 2 to 20 carbon atoms; a branched hydrocarbyl group having 3 to 20 carbon atoms or cyclic hydrocarbyl group having 5 to 20 carbon atoms;
R is independently a monovalent hydrocarbyl group which is selected from alkyl groups having from 1 to 18 carbon atoms, aryl groups having from 6 to 10 carbon atoms, and cyclic hydrocarbyl groups having from 5 to 10 carbon atoms;
L1 is a covalent bond or a divalent linking group , - 33a -in which R1 and R2 are defined above;
p is the integer 1, 2, or 3.

3. The pressure-sensitive adhesive compositions according to claim 2 wherein the divalent polymeric group Z of said graft polymer has the general formula:

wherein:
each of R3, R4, and R5 is independently hydrogen, a phenyl group, an alkyl group having 1 to 12 carbon atoms, and alkenyl group having 2 to 12 carbon atoms, or any two of R3, R4, and R5 together with the carbon atoms to which theyare attached form one or two saturated or unsaturated 5 or 6 carbon atom-containing rings;
R6 is an aryl group having 6 to 18 carbon atoms, optionally substituted by lower alkyl groups having from 1 to 4 carbon atoms, trialkylsilyl, 2,2-dialkyl alkoxysilyl, N,N-bis(trimethylsilyl)amino, and trimethylsiloxyethyl groups; and 1,1-dimethylethoxycarbonyl; and x, y, and z are numbers providing a number average molecular weight of 2,000 to 30,000 to the polymeric Z group and expressing the number of ethenylarene and conjugated diene groups that are present in random or block configurations in the polymeric Z group, in which numbers any of x, y and z can be zero, but at least one of x, y and z is not zero.

4. The pressure-sensitive adhesive composition of claims 1 to 3 wherein said graft copolymer is selected from graft copolymers having the following formulae:

wherein L, L1, Z, R°, R, p and n are defined above;
R7 is hydrogen or one or more alkyl groups having 1 to 16 carbon atoms, at least 60% of R7 being allyl groups having 4 to 12 carbon atoms; and a and b are numbers expressing the number of macromonomer units and .alpha.-olefin units randomly located in the graft polymer chain and providing a number average molecular weight of 50,000 to 10,000,000 to the graft polymer, and a having a value that is 0.1 to 25% (by weight) of (a + b).

5. The pressure-sensitive adhesive composition according to claims 1 to 4 wherein said graft copolymer is phase-separated into rubbery regions and glassy regions.

6. The pressure-sensitive adhesive composition according to claims 1 to 5 wherein the macromolecular monomcr has a number average molecular weight of from 2,000 to 30,000, and wherein said graft copolymer has anumber average molecular weighe of from 50,000 to 10 million.

7. The pressure-sensitive adhesive composition according to claims 1 to 6 wherein said pressure-sensitive adhesive is heat activated, or hot-tackifying.

8. An article comprising the adhesive composition according to claims 1 to 7 coated on a substrate which optionally further comprises at least one of a primer layer and a release liner.

9. The article according to claim 8 which is a pressure-sensitive adhesive tape or a transfer adhesive film.

10. A laminated structure comprising at least two substrates, and coated therebetween a layer of the adhesive composition according to claims 1 to 7.